1. Field of the Invention
This invention relates to slidable suspensions for trailers and more particularly to an apparatus for attaching a trailing arm air spring suspension to a sliding frame.
2. Scope of the Prior Art
Sliders are frequently used with truck trailers where it is desirable to adjust the space between the trailer axles and the drive axles on the tractor. Typically, the trailer is formed with a structural boxlike container. Unlike conventional trailers, there is no frame beneath the container. Rigidity is achieved through the construction of the container. A pair of rails are mounted at a rear portion of the trailer, and the slider is mounted to the rails for slidable movement in a fore and aft direction. The slider includes a subframe with axles and wheels suspended from the subframe. When the slider and its suspension is moved in the aft direction, the spacing between the trailer axles and the drive axles on the tractor is increased. Conversely, when the slider is moved in the forward direction, the spacing is decreased.
Typically, sliders utilize leaf springs to suspend the axles from the subframe. Leaf spring suspensions are considerably less expensive and lighter in weight than air suspensions which include a pivotable trailing arm and an air spring. However, the ride provided by a leaf spring suspension tends to be relatively harsh which negatively affects vehicle durability, promotes cargo damage, and adversely affects the control of the tractor and trailer. To a lesser degree, air spring suspensions are used on slidable trailers. Air spring suspensions provide a smoother ride and improve the control of the tractor and trailer. However, a typical air spring suspension has less connections for conducting lateral forces to the subframe than a leaf spring suspension. Thus, more stress is placed on the connections for an air spring suspension. Prior solutions to the problem have been directed at providing heavier-weight metal and strengthening rigid connections between the air spring suspension and the frame.